Yup it's got to be done, even if you know everything in it (amd much more).
Useful for the entry list I find, though I buy one of the local rags to refere to at the circuit, tear off the back page and stick it in my pocket.
Resisting the temptation to open mine 'till the train home.
Your right Piglet, just buying the guide bought a little of the Sarthe buzz to Holborn. We'll be on Speed Ferries One exactly a week from now.